Porpita edit

Introduction edit

Porpita is a genus of the phylum Cnidarian. Similar to the well-known Portuguese Man-of-War, species in this genus are mainly comprised of colonies of hydrozoans, linked to a biological float, keeping them near the surface. Unlike the Man-of-War, however, the porpita lacks a sail and therefore does not get blown ashore as often.[1]

Organisms from this genus reside in tropical to sub-tropical waters all around the world. Like other cnidarians, organisms from this genus possess stinging cells called cnidoblasts. The most common species of this genus is the Porpita porpita, more commonly known as the "Blue Button Jellyfish."[2]

Tmolite/sandbox
 
Blue button (Porpita porpita)
Scientific classification  
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Order: Anthoathecata
Family: Porpitidae
Genus: Porpita
Lamarck, 1801
Species

Anatomy edit

Porpita resides in the class Hydrozoa, and phylum Cnidaria, and therefore possesses similar features to jellyfish, hydrozoans, and other stinging marine animals. The animals in this genus possess zooids, which is essentially a small group of the same organism binding together to make a larger organism, however each zooid serves a specific purpose. Some are active hunter zooids, some are digestive, some are responsible for the makeup of the body, but they all group together to form the main body.[3]
Most organisms in the genus are part of a group of organisms called chondrophores.[4] Development requires a polyp stage in which the individual zooids develop and combine into colonies.There is a bell-like medusa structure made of a gas-filled membrane, which is a feature found in all others of this group. This flotation device is used to keep them on the surface of the water. They possess nematocysts, however research has proven that the sting from these organisms is not lethal and only causes minor skin irritation. These cells are found in their branching tentacles that are used to capture prey.

Food edit

A study was conducted on a group of Porpita that had washed up along the shore of a Japanese beach. Their internal organs were removed and the food contents were examined. It was found that these animals are carnivorous, eating mostly copepods and some larval fish.[5] The size of the food was relatively proportional to the size of the animal. There was also a small amount of crustaceans found, mainly exoskeleton remains. The trend in food choice leads scientists to believe that these hydrozoans are active hunters, pursuing active prey items.

Habitats edit

Organisms of the phylum Porpita typically are found in the Atlantic, Indo-Pacific oceans and the Mediterranean Sea. While there are reports of a small abundance near the northwest Indian Oceans, there is too great a lack in research and sightings in this region to deem it a place where Porpita typically reside.[6] Possessing similar body structure to their evolutionary relative, the Portuguese Man-of-War, they reside near or on the surface of the ocean in the euphotic zone where there is an abundance of zooplankton to feed on.

Some species of the Genus, like the Porpita porpita, are more typically found in the crashing waves of the seas or in rocky intertidal regions. They vary greatly in size and can often be found stuck to rocks or floating in a small tide pool. They thrive mostly in very warm areas with high salinity waters, making the waters near the middle east and south Europe a suitable place for them.[7]

Human Interaction edit

Often washing up on the coast of Florida, these particular hydrozoans do not possess a significant sting. Beachgoers that have come across them often say the sting is very minimal, if noticeable at all. Very little is known about these organisms, seeing how there are only two species to the entire genus. Most research has been done on the blue button, simply because it is the only Porpita organism readily visible for research purposes.

Abundance and Conservation edit

There are no known conservation efforts for species within the genus Porpita because they are not abundant enough for scientists to determine their benefit or detriment to the surrounding ecosystem. Hydrozoans as a whole frequently have blooms and can cause extreme nutrient depletion for other surrounding organisms. In regards to impact on humans, there have been no recorded cases of negative human influence either by the presence or lack thereof for these organisms. Similar evolutionary relatives can be lethal to humans, but these species of Porpita are no great risk to us.[8] More research is needed to determine just how vital of a role they play in the ocean.

Sources edit

  1. ^ Meinkoth, Norman August (1981). The Audubon Society Field Guide to North American Seashore Creatures. A.A. Knopf. ISBN 9780394519937.
  2. ^ "Blue Button Jellyfish (Porpita porpita) blue jellyfish with fringe". www.beachhunter.net. Retrieved 2019-04-13.
  3. ^ Kennedy, Jennifer (November 16th, 2018). "Learn About the Blue Button Jelly". {{cite web}}: Check date values in: |date= (help)
  4. ^ "Porpita prunella", Wikipedia, 2018-09-26, retrieved 2019-04-13
  5. ^ Beirie, Robert (Summer 1970). "THE FOOD OF PORPITA AND NICHE SEPARATION IN THREE NEUSTON COELENTERATES" (PDF). Kyoto University Research Information Repository. 5: 305–307.
  6. ^ Gul, Shahnawaz; Gravili, Cinzia (2014). "On the occurrence of Porpita porpita (Cnidaria: Hydrozoa) at Pakistan coast (North Arabian Sea)". Marine Biodiversity Records. 7. doi:10.1017/S1755267214000189. ISSN 1755-2672.
  7. ^ Saygın, Özlem (2017-06-20). "On the occurrence of blue button, Porpita porpita (Cnidaria: Hydrozoa) from Levantine coast of Turkey". Natural and Engineering Sciences. 2 (2): 33–36. doi:10.28978/nesciences.328905. ISSN 2458-8989.
  8. ^ "The Wonders of the Seas: Cnidarians". www.oceanicresearch.org. Retrieved 2019-04-13.